Scoop vs Tapped horn

After reading a lot about tapped horn I got thinking about the two design and which one would have lower extension (play low) and have more spl and the pros and cons of each design.    We know that size of the enclosure play's a big part of the equation I did so quick calculations of three of them . The Hog scoop ,The Super scoop and the T18 .    The hog comes in at 21.038 cf or 595L      The super scoop at 20.825cf or 589L    The T18 is 14.832cf or 419L.   Now to my understanding of the pro of scoops based on HR they appear to be a little more efficient than tapped horn and when a group of four they gain some extension on the low end .now the con due to there phase problem can't play over 90/100 hz.   Now to the tapped horn pros play low in 1 box has directionality of the sound and generally are smaller .cons you get no additional extension from adding more. Please provide information if any of the information is wrong. Now the Question which of the designs will provide the lowest notes and highs spl all things being equal including the driver let's say the B&C 18sw115 the reason I use it is because its used in both designs.   It would be nice if we have some actual measures of scoops to compare. I'm hoping to get some good feedback on the topic.

I have always wondered why OT horns aren't more prevalent in the soundsystem world.
A friend of mine keeps raving about them and doing sim after sim after sim.
I've always believed to find things out for myself, so I may just build an OT horn and A/B test it against one of my superscoops. 

What is a OT horn? Never heard of them...

Is it a scoop? Tapped horn?

Meat wrote: It's a fairly large and long tapped horn. http://www.data-bass.com/data?page=system&id=81

Thanks

After a lot more reading on the OT horn it appears that the trade off the design was willing to give up was some SPL and for some low in extension but knowing it has